* {
  box-sizing: border-box;
}

/* 清除内外边距 */
body, h1, h2, h3, h4, h5, h6, hr, p, blockquote, /* structural elements 结构元素 */
dl, dt, dd, ul, ol, li, /* list elements 列表元素 */
pre, /* text formatting elements 文本格式元素 */
fieldset, lengend, button, input, textarea, /* form elements 表单元素 */
th, td { /* table elements 表格元素 */
  margin: 0;
  padding: 0;
}

ul, ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: normal;
}

a, a:link, a:visited, a:hover, a:active {
  outline: 0;
  text-decoration: none;
}

img {
  border: none;
  text-decoration: none;
}
